WASHINGTON — Republican presidential candidate Mitt Romney on Friday released income-tax returns showing that he and his wife, Ann, paid an effective tax rate of 14.1 percent last year.

The Romneys, who filed their 2011 taxes Friday, paid $1.9 million in taxes on $13.7 million in income, most of it from investments. They donated $4 million to charity, about 30 percent of their income, but deducted only $2.25 million of it to keep their tax bill above 13 percent, as Romney had promised during his campaign.

He could still deduct the unclaimed amount of his charitable donations in future tax years, experts said.

Romney’s campaign also released a notarized summary from PricewaterhouseCoopers, the family’s tax preparer, declaring that the former Massachusetts governor and business executive paid taxes every year between 1990 and 2009 and saying the average tax rate was 20.2 percent. It said he paid an effective tax rate of at least 13.66 percent every year.

That countered unsubstantiated charges from Senate Majority Leader Harry Reid, D-Nev., that Romney hadn’t paid taxes in 10 years. Reid said he was told that by an unidentified investor at Bain Capital, the company that Romney co-founded.

The furor over Romney’s taxes had prompted other Democrats and several Republicans to demand that he provide more tax information than the 2010 records and 2011 estimates he released this year.

Romney had said he would release the 2011 data when it became available, but he has consistently argued that giving more tax details would only give President Obama’s campaign more ammunition.

The tax return shows that Romney’s income came in far lower than he had expected in January, when he filed an estimated tax return that projected he would earn $20.9 million.

The $7.2 million drop in his expected income was explained by the Romney campaign as a result of variations in his investment returns that he could not have foreseen in January.

On average, middle-income families, those making from $50,000 to $75,000 a year, pay 12.8 percent of their income in federal taxes, according to Congress’ Joint Committee on Taxation.

Friday’s release did nothing to satisfy Obama’s campaign, Democrats and other Romney critics.

“Today’s release of Mitt Romney’s 2011 tax returns confirms what we already knew, that people like Mitt Romney pay a lower tax rate than many middle-class families because of a set of complex loopholes and tax shelters only available to those at the top,” said Stephanie Cutter, Obama’s deputy campaign manager.

Reid was not satisfied, either. “The information released today reveals that Mitt Romney manipulated one of the only two years of tax returns he’s seen fit to show the American people — and then only to ‘conform’ with his public statements,” Reid said. “That raises the question: ‘What else in those returns has Romney manipulated?’ “

Fred Goldberg, a former IRS commissioner, said the Romneys “have fully satisfied their responsibilities as taxpayers.”

Romney makes most of his money now from investments, which are generally taxed at 15 percent, a lower rate than a salary; the top marginal rate for income from wages is 35 percent.

Earlier his year, Romney defended his 2010 tax return, noting that he took all of the deductions allowed by law.

“I don’t pay more than are legally due, and frankly if I had paid more than are legally due, I don’t think I’d be qualified to become president,” he told ABC News.

Since then, however, he decided not to deduct all of his charitable contributions from his taxable income in 2011 because that would have reduced his tax bill below 13 percent of his total income, aides said. He had said in the campaign that he never paid less than that.

In 2011, the Romney’s charitable cash contributions included $1.115 million to the Mormon church and $214,516 to Tyler Charitable Foundation, a Romney family foundation. The Romneys also claimed a deduction of $920,573 for noncash contributions that were not spelled out in a statement accompanying the return.

A good portion of the Romney fortune has been invested abroad, managed by a blind trust that is out of his control.

The blind trust as of Dec. 31, 2011, held shares of Germany-based sporting-goods company adidas, Chinese oil company CNOOC, Russian natural-gas powerhouse Gazprom, Japanese carmaker Toyota, German auto giant Volkswagen and foreign banks including Germany’s Deutsche Bank, Brazil’s Itaú and the disgraced Swiss bank Credit Suisse, which agreed to a $556 million settlement in 2009 with U.S. authorities who alleged it had help Iran skirt U.S. financial sanctions.

The foreign investments put the trustee of Romney’s blind trust, R. Bradford Malt, in awkward positions. In June, Malt disposed of shares of Chinese video giant Youku.com at a loss about a month after acquiring them.

Although the firm was breaking out as China’s version of YouTube, it also has become a den for pirating movies and DVDs. Romney, on the campaign trail, had criticized Chinese piracy.

As with the Romneys’ 2010 return, the 2011 return made fleeting mention of a series of offshore investments through tax havens such as the Cayman Islands, Ireland and Luxembourg.

Obama’s tax return for last year showed that he and his wife, Michelle, paid $162,074 in federal taxes on $789,674 in adjusted gross income, an effective tax rate of 20.5 percent. Their income plunged from $1.7 million in 2010, with declining sales of the president’s books. In 2009, the Obamas reported income of $5.5 million.

Material from The Associated Press and The New York Times is included in this report.